Field of the Invention
The present invention relates to CD3-binding molecules capable of binding to human and non-human CD3, and in particular to such molecules that are cross-reactive with CD3 of a non-human mammal (e.g., a cynomolgus monkey). The invention also pertains to uses of such antibodies and antigen-binding fragments in the treatment of cancer, autoimmune and/or inflammatory diseases and other conditions.
Description of Related Art
The body's immune system serves as a defense against a variety of conditions, including, e.g., injury, infection and neoplasia, and is mediated by two separate but interrelated systems: the cellular and humoral immune systems. Generally speaking, the humoral system is mediated by soluble products (antibodies or immunoglobulins) that have the ability to combine with and neutralize products recognized by the system as being foreign to the body. In contrast, the cellular immune system involves the mobilization of certain cells, termed T cells, that serve a variety of therapeutic roles. T cells are lymphocytes that are derived from the thymus and circulate between the tissues, lymphatic system and the circulatory system. They act against, or in response to, a variety of foreign structures (antigens). In many instances these foreign antigens are expressed on host cells as a result of neoplasia or infection. Although T cells do not themselves secrete antibodies, they are usually required for antibody secretion by the second class of lymphocytes, B cells (which derive from bone marrow). Critically, T cells exhibit extraordinary immunological specificity so as to be capable of discerning one antigen from another).
A naive T cell, e.g., a T cell which has not yet encountered its specific antigen, is activated when it first encounters a specific peptide:MHC complex on an antigen presenting cell. The antigen presenting cell may be a B cell, a macrophage or a dendritic cell. When a naive T cell encounters a specific peptide:MHC complex on an antigen presenting cell, a signal is delivered through the T-cell receptor which induces a change in the conformation of the T cell's lymphocyte function associated antigen (LFA) molecules, and increases their affinity for intercellular adhesion molecules (ICAMs) present on the surface of the antigen presenting cell. The signal generated by the interaction of the T cell with an antigen presenting cell is necessary, but not sufficient, to activate a naive T cell. A second co-stimulatory signal is required. The naive T cell can be activated only by an antigen-presenting cell carrying both a specific peptide MHC complex and a co-stimulatory molecule on its surface. Antigen recognition by a naive T cell in the absence of co-stimulation results in the T cell becoming anergic. The need for two signals to activate T cells and B cells such that they achieve an adaptive immune response may provide a mechanism for avoiding responses to self-antigens that may be present on an antigen presenting cell at locations in the system where it can be recognized by a T cell. Where contact of a T cell with an antigen presenting cell results in the generation of only one of two required signals, the T cell does not become activated and an adaptive immune response does not occur.
The efficiency with which humans and other mammals develop an immunological response to pathogens and foreign substances rests on two characteristics: the exquisite specificity of the immune response for antigen recognition, and the immunological memory that allows for faster and more vigorous responses upon re-activation with the same antigen (Portoles, P. et al. (2009) “The TCR/CD3 Complex: Opening the Gate to Successful Vaccination,” Current Pharmaceutical Design 15:3290-3300; Guy, C. S. et al. (2009) “Organization of Proximal Signal Initiation at the TCR: CD3 Complex,” Immunol Rev. 232(1):7-21). The specificity of the response of T-cells is mediated by the recognition of antigen (displayed on Antigen-Presenting Cells (APCs) by a molecular complex involving the T Cell Receptor (“TCR”) and the cell surface receptor ligand, CD3. The TCR is a covalently linked heterodimer of α and β chains (“TCRαβ”). These chains are class I membrane polypeptides of 259 (α) and 296 (β) amino acids in length. The CD3 molecule is a complex containing a CD3 γ chain, a CD3 δ chain, and two CD3 ε chains associated as three dimers (εγ, εδ, ζζ) (Guy, C. S. et al. (2009) “Organization of Proximal Signal Initiation at the TCR: CD3 Complex,” Immunol Rev. 232(1):7-21; Call, M. E. et al. (2007) “Common Themes In The Assembly And Architecture Of Activating Immune Receptors,” Nat. Rev. Immunol. 7:841-850; Weiss, A. (1993) “T Cell Antigen Receptor Signal Transduction: A Tale Of Tails And Cytoplasmic Protein-Tyrosine Kinases,” Cell 73:209-212). The TCR and CD3 complex, along with the CD3 ζ chain zeta chain (also known as T-cell receptor T3 zeta chain or CD247) comprise the TCR complex (van der Merwe, P. A. etc. (epub Dec. 3, 2010) “Mechanisms For T Cell Receptor Triggering,” Nat. Rev. Immunol. 11:47-55; Wucherpfennig, K. W. et al. (2010) “Structural Biology of the T-cell Receptor: Insights into Receptor Assembly, Ligand Recognition, and Initiation of Signaling,” Cold Spring Harb. Perspect. Biol. 2:a005140). The complex is particularly significant since it contains a large number (ten) of immunoreceptor tyrosine-based activation motifs (ITAMs).
In mature T cells, TCR/CD3 activation by foreign antigenic peptides associated to self-MHC molecules is the first step needed for the expansion of antigen-specific T cells, and their differentiation into effector or memory T lymphocytes. These processes involve the phosphorylation of the immunoreceptor tyrosine-based activation motifs (ITAMs) of the TCR complex. Because the TCR complex has such a large number of ITAMS (10 in all), and these ITAMS are arrayed in tandem (due to the dimerization of the constituent chains), phosphorylation of the relevant tyrosine residues upon TCR ligation creates paired docking sites for proteins that contain Src homology 2 (SH2) domains such as the ζ chain-associated protein of 70 kDa (ZAP-70), and thereby initiate an amplifying signaling cascade which leads to T-cell activation and differentiation (Guy, C. S. et al. (2009) “Organization of Proximal Signal Initiation at the TCR: CD3 Complex,” Immunol Rev. 232(1):7-21).
The outcome of these processes is modulated by the intensity and quality of the antigen stimulus, as well as by the nature of accompanying signals delivered by co-receptor and co-stimulatory surface molecules, or by cytokine receptors (Portolés, P. et al. (2009) “The TCR/CD3 Complex: Opening the Gate to Successful Vaccination,” Current Pharmaceutical Design 15:3290-3300; Riha, P. et al. (2010) “CD28 Co-Signaling In The Adaptive Immune Response,” Self/Nonself 1(3):231-240). Although TCR stimulation is a prerequisite for T-cell activation, it is well recognized that engagement of co-stimulatory molecules, such as CD28, is necessary for full T-cell activation and differentiation (Guy, C. S. et al. (2009) “Organization of Proximal Signal Initiation at the TCR: CD3 Complex,” Immunol Rev. 232(1):7-21).
Due to the fundamental nature of CD3 in initiating an anti-antigen response, monoclonal antibodies against this receptor have been proposed as being capable of blocking or at least modulating the immune process and thus as agents for the treatment of inflammatory and/or autoimmune disease. Indeed, anti-CD3 antibodies were the first antibody approved for the human therapy (St. Clair E. W. (2009) “Novel Targeted Therapies for Autoimmunity,” Curr. Opin. Immunol. 21(6):648-657). Anti-CD3 antibody (marketed as ORTHOCLONE™ OKT3™ by Janssen-Cilag) has been administered to reduce acute rejection in patients with organ transplants and as a treatment for lymphoblastic leukemia (Cosimi, A. B. et al. (1981) “Use Of Monoclonal Antibodies To T-Cell Subsets For Immunologic Monitoring And Treatment In Recipients Of Renal Allografts,” N. Engl. J. Med. 305:308-314; Kung, P. et al. (1979) Monoclonal antibodies defining distinctive human T cell surface antigens,” Science 206:347-349; Vigeral, P. et al. (1986) “Prophylactic Use Of OKT3 Monoclonal Antibody In Cadaver Kidney Recipients. Utilization Of OKT3 As The Sole Immunosuppressive Agent,” Transplantation 41:730-733; Midtvedt, K. et al. (2003) “Individualized T Cell Monitored Administration Of ATG Versus OKT3 In Steroid-Resistant Kidney Graft Rejection,” Clin. Transplant. 17(1):69-74; Gramatzki, M. et al. (1995) “Therapy With OKT3 Monoclonal Antibody In Refractory T Cell Acute Lymphoblastic Leukemia Induces Interleukin-2 Responsiveness,” Leukemia 9(3):382-390; Herold, K. C. et al. (2002) “Anti-CD3 Monoclonal Antibody In New-Onset Type 1 Diabetes Mellitus,” N. Engl. J. Med. 346:1692-1698; Cole, M. S. et al. (1997) “Human IgG2 Variants Of Chimeric Anti-CD3 Are Nonmitogenic to T cells,” J. Immunol. 159(7):3613-3621; Cole, M. S. et al. (1999) “Hum291, A Humanized Anti-CD3 Antibody, Is Immunosuppressive To T Cells While Exhibiting Reduced Mitogenicity in vitro,” Transplantation 68:563-571; U.S. Pat. Nos. 6,491,916; 5,585,097 and 6,706,265).
However, such anti-CD3 treatment has not proven to be specific enough to avoid side effects (Ludvigsson, J. (2009) “The Role of Immunomodulation Therapy in Autoimmune Diabetes,” J. Diabetes Sci. Technol. 3(2):320-330). Repeated daily administration of OKT3 results in profound immunosuppression and provides effective treatment of rejection following renal transplantation. The in vivo administration of OKT3 results in both T cell activation and suppression of immune responses. However, the use of OKT3 has been hampered by a first toxic dose reaction syndrome that is related to initial T-cell activation events and to the ensuing release of cytokines that occurs before immunosuppression of T cell responses. The reported side effects that follow the first and sometimes the second injection of this mouse monoclonal antibody include a “flu-like” syndrome consisting of high fever, chills, headache, and gastrointestinal symptoms (vomiting and diarrhea) and in severe cases pulmonary edema within hours of treatment has been noted (Thistlethwaite, J. R. Jr. et al. (1988) “Complications and Monitoring of OKT3 Therapy,” Am. J. Kidney Dis. 11:112-119). This syndrome is believed to reflect OKT3-mediated cross-linking of the TCR/CD3 complex on the T cell surface and the resultant release of cytokines (e.g., tumor necrosis factor alpha (TNFα), interferon-γ, interleukins IL-2, IL-3, IL-4, IL-6, IL-10 and granulocyte-macrophage colony-stimulating factor (Masharani, U. B. et al. (2010) “Teplizumab Therapy For Type 1 Diabetes,” Expert Opin. Biol. Ther. 10(3):459-465; Abramowicz, D. et al. (1989) “Release Of Tumor Necrosis Factor, Interleukin-2, And Gamma-Interferon In Serum After Injection Of OKT3 Monoclonal Antibody In Kidney Transplant Recipients,” Transplantation 47:606-608; Ferran, C. et al. (1990) “Cytokine-Related Syndrome Following Injection Of Anti-CD3 Monoclonal Antibody: Further Evidence For Transient In Vivo T Cell Activation,” Eur. J. Immunol. 20:509-515; Hirsch, R. et al. (12989) “Effects Of In Vivo Administration Of Anti-CD3 Monoclonal Antibody On T Cell Function In Mice. II. In Vivo Activation Of T Cells,” J. Immunol. 142:737-743). The use of anti-CD3 antibodies is disclosed in U.S. Pat. Nos. 7,883,703; 7,728,114; 7,635,472; 7,575,923; and 7,381,903, and in United States Patent Publications Nos. 2010/0150918; 2010/0209437; 2010/0183554; 2010/0015142, 2008/0095766, 2007/0077246 and in PCT Publication WO2008/119567.
A particular limitation of prior antibodies is their specificity for only human CD3. This limitation is a significant impediment to the development of such antibodies as therapeutic agents for the treatment of human diseases. In order to obtain market approval any new candidate medication must pass through rigorous testing. This testing can be subdivided into preclinical and clinical phases. Whereas the latter—further subdivided into the generally known clinical phases I, II and III—is performed in human patients, the former is performed in animals. The aim of preclinical testing is to prove that the drug candidate has the desired activity and most importantly is safe. Only when the safety in animals and possible effectiveness of the drug candidate has been established in preclinical testing this drug candidate will be approved for clinical testing in humans by the respective regulatory authority. Drug candidates can be tested for safety in animals in the following three ways, (i) in a relevant species, i.e., in a species where the drug candidates can recognize the ortholog antigens, (ii) in a transgenic animal containing the human antigens and (iii) by use of a surrogate for the drug candidate that can bind the ortholog antigens present in the animal. Limitations of transgenic animals are that this technology is typically limited to rodents. However, rodents and humans have significant differences in physiology that may complicate the extrapolation of safety data obtained in rodents to predict safety in humans. The limitations of a surrogate for the drug candidate are the different composition of matter compared to the actual drug candidate and often the animals used are rodents with the limitation as discussed above. Therefore, preclinical data generated in rodents are of limited predictive power with respect to the drug candidate. The approach of choice for safety testing is the use of a relevant species, preferably a lower primate. The limitation now of the CD3 binding molecules suitable for therapeutic intervention in man described in the art is that the relevant species are higher primates, in particular cynomolgus monkeys. Accordingly, an anti-CD3 antibody capable of binding to both human and primate CD3 is highly desirable. Such antibodies have been described in United States Patent Publication No. 20100150918 and in PCT Publication WO2008/119567.
Despite such advances, a need remains for anti-human CD3 antibodies and their antigen-binding fragments that are capable of cross-reacting with CD3 of a non-human mammal (e.g., a cynomolgous monkey). The present invention addresses this need and the need for improved therapeutics for cancer, autoimmunity and inflammatory diseases.